millionco · skoshx · Jul 29, 2026 · Jul 29, 2026
diff --git a/.changeset/git-dir-scoped-scan.md b/.changeset/git-dir-scoped-scan.md
@@ -0,0 +1,7 @@
+---
+"@react-doctor/core": patch
+---
+
+fix: clear GIT_DIR for nested git commands in scoped scans
+
+Git hooks export `GIT_DIR`, which causes nested git commands to ignore the scoped `cwd` and return repository-root paths. This fix explicitly clears `GIT_DIR` when spawning git commands while preserving other environment variables like `GIT_INDEX_FILE`.
diff --git a/packages/core/src/services/git.ts b/packages/core/src/services/git.ts
@@ -443,7 +443,13 @@ export class Git extends Context.Service<
               // default; ChildProcess's option flips the polarity.)
               ChildProcess.make(input.command, [...input.args], {
                 cwd: input.directory,
-                env: input.env,
+                env:
+                  input.command === "git"
+                    ? {
+                        ...input.env,
+                        GIT_DIR: undefined,
+                      }
+                    : input.env,
                 extendEnv: true,
               }),
             );

diff --git a/packages/core/tests/regressions/issue-1501-git-dir-scoped-scan.test.ts b/packages/core/tests/regressions/issue-1501-git-dir-scoped-scan.test.ts
@@ -0,0 +1,156 @@
+import * as child_process from "node:child_process";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+import * as Effect from "effect/Effect";
+import { afterAll, describe, expect, it } from "vite-plus/test";
+import { Git } from "@react-doctor/core";
+
+const runNode = <Value>(program: Effect.Effect<Value, unknown, Git>): Promise<Value> =>
+  Effect.runPromise(program.pipe(Effect.provide(Git.layerNode)));
+
+const setupLinkedWorktreeRepo = (): { mainRepoPath: string; linkedWorktreePath: string } => {
+  const tempRoot = fs.mkdtempSync(path.join(os.tmpdir(), "rd-1501-"));
+  const mainRepoPath = path.join(tempRoot, "main-repo");
+  const linkedWorktreePath = path.join(tempRoot, "linked-worktree");
+
+  child_process.execSync("git init", { cwd: tempRoot, stdio: "ignore" });
+  fs.renameSync(path.join(tempRoot, ".git"), path.join(tempRoot, "main-repo"));
+
+  fs.mkdirSync(path.join(mainRepoPath, "webapp"), { recursive: true });
+  fs.writeFileSync(path.join(mainRepoPath, "webapp", "index.html"), "<html></html>");
+  fs.writeFileSync(path.join(mainRepoPath, "webapp", "app.js"), "console.log('app');");
+
+  child_process.execSync("git config user.email 'test@example.com'", {
+    cwd: mainRepoPath,
+    env: { ...process.env, GIT_DIR: mainRepoPath },
+    stdio: "ignore",
+  });
+  child_process.execSync("git config user.name 'Test User'", {
+    cwd: mainRepoPath,
+    env: { ...process.env, GIT_DIR: mainRepoPath },
+    stdio: "ignore",
+  });
+  child_process.execSync("git add .", {
+    cwd: mainRepoPath,
+    env: { ...process.env, GIT_DIR: mainRepoPath },
+    stdio: "ignore",
+  });
+  child_process.execSync("git commit -m 'initial'", {
+    cwd: mainRepoPath,
+    env: { ...process.env, GIT_DIR: mainRepoPath },
+    stdio: "ignore",
+  });
+
+  child_process.execSync(`git worktree add ${linkedWorktreePath} -b feature`, {
+    cwd: mainRepoPath,
+    env: { ...process.env, GIT_DIR: mainRepoPath },
+    stdio: "ignore",
+  });
+
+  fs.writeFileSync(path.join(linkedWorktreePath, "webapp", "app.js"), "console.log('modified');");
+
+  return { mainRepoPath, linkedWorktreePath };
+};
+
+const testRepo = setupLinkedWorktreeRepo();
+
+afterAll(() => {
+  fs.rmSync(path.dirname(testRepo.mainRepoPath), { recursive: true, force: true });
+});
+
+describe("issue #1501: scoped scans fail inside Git hooks when GIT_DIR is set", () => {
+  it("returns paths relative to the scoped directory when GIT_DIR is set", async () => {
+    const webappPath = path.join(testRepo.linkedWorktreePath, "webapp");
+
+    const originalGitDir = process.env.GIT_DIR;
+    process.env.GIT_DIR = testRepo.mainRepoPath;
+
+    try {
+      const result = await runNode(
+        Effect.gen(function* () {
+          const git = yield* Git;
+          return yield* git.diffSelection({
+            directory: webappPath,
+            explicitBaseBranch: "HEAD",
+          });
+        }),
+      );
+
+      expect(result).not.toBeNull();
+      if (result !== null) {
+        expect(result.changedFiles).toEqual(["app.js"]);
+      }
+    } finally {
+      if (originalGitDir === undefined) {
+        delete process.env.GIT_DIR;
+      } else {
+        process.env.GIT_DIR = originalGitDir;
+      }
+    }
+  });
+
+  it("does not return repository-root paths when scanning a subdirectory with GIT_DIR set", async () => {
+    const webappPath = path.join(testRepo.linkedWorktreePath, "webapp");
+
+    const originalGitDir = process.env.GIT_DIR;
+    process.env.GIT_DIR = testRepo.mainRepoPath;
+
+    try {
+      const result = await runNode(
+        Effect.gen(function* () {
+          const git = yield* Git;
+          return yield* git.diffSelection({
+            directory: webappPath,
+            explicitBaseBranch: "HEAD",
+          });
+        }),
+      );
+
+      if (result !== null) {
+        for (const filePath of result.changedFiles) {
+          expect(filePath).not.toContain("webapp/");
+          expect(path.isAbsolute(filePath)).toBe(false);
+        }
+      }
+    } finally {
+      if (originalGitDir === undefined) {
+        delete process.env.GIT_DIR;
+      } else {
+        process.env.GIT_DIR = originalGitDir;
+      }
+    }
+  });
+
+  it("preserves GIT_INDEX_FILE when clearing GIT_DIR", async () => {
+    const webappPath = path.join(testRepo.linkedWorktreePath, "webapp");
+    const originalGitDir = process.env.GIT_DIR;
+    const originalGitIndexFile = process.env.GIT_INDEX_FILE;
+    const customIndexPath = path.join(testRepo.linkedWorktreePath, ".git", "custom-index");
+
+    process.env.GIT_DIR = testRepo.mainRepoPath;
+    process.env.GIT_INDEX_FILE = customIndexPath;
+
+    try {
+      const result = await runNode(
+        Effect.gen(function* () {
+          const git = yield* Git;
+          return yield* git.currentBranch(webappPath);
+        }),
+      );
+
+      expect(result).toBe("feature");
+    } finally {
+      if (originalGitDir === undefined) {
+        delete process.env.GIT_DIR;
+      } else {
+        process.env.GIT_DIR = originalGitDir;
+      }
+      if (originalGitIndexFile === undefined) {
+        delete process.env.GIT_INDEX_FILE;
+      } else {
+        process.env.GIT_INDEX_FILE = originalGitIndexFile;
+      }
+    }
+  });
+});